The paper of Kouznetsov did not get as popular as some here expected , but I - as a skeptic - did.

One of the reasons might be this :

INTEGRAL TRANSFORMS HAVE CONDITIONS !

A good example is the Mellin inversion theorem.

Those conditions can be quite complex.

If an equation involved unknown functions AND integral transforms , it is a bit handwaving to assume all the conditions are met + uniqueness AND existance.

From my experience in number theory , many of my " unpublished wrong crank ideas " were mistakes by assuming conditions of integral transforms holds.

One could easily prove RH , collatz and Hardy-Littlewood I or II with those silly integrals , that turn out not to be valid in some sense ( conditions not met , some formula's not valid , divergence , summability method fail/dubious , using assumptions equivalent to the whole conjecture , assuming differentiability , ... )

Most pro mathematicians see this immediately.

I am unaware of any paper that adresses these issues , and I assume nobody is willing to pay for it before being convinced.

You see , tetration is not mainstraim , so the access should be easy and the burden of proof is on the claimer side.

Don't get me wrong , I like Kouznetsov and some of his ideas.

But those are my viewpoints , and by the lack of popularity of his paper ( in retrospect years later ) I assume it is the view of most.